Structure, Tectonics, and Stratigraphy

Associated Faculty:

C. J. Northrup, Walter S. Snyder, Mark Schmitz

Overview:

Structural Geology is the aspect of geosciences that examines the products and processes of deformation within the Earth. It integrates information and observations at a wide variety of scales - from the bending and breaking atomic bonds during deformation of a crystal lattice, to the bending, breaking and deformation of lithosphere during the creation of a mountain belt. Structural geology is one cornerstone of Tectonics , which is the study of the multifaceted evolution of entire orogenic systems. Plate tectonic theory provides a framework in which we can organize and understand a wide variety of different geologic phenomena and their interactions. Because tectonics integrates a diverse spectrum of processes in geology, tectonic research is commonly multidisciplinary in scope.

Projects:

Structure and timing of thrust emplacement of the Golconda Allochthon, western Nevada:
Classically, the emplacement of the Golconda Allochthon onto the western margin of North America has been attributed to the Sonoma Orogeny in Permo-Trassic time. Critical evaluation of the available timing constrains, however, allows east-directed transport of the allochthon to have occurred as late as the middle Jurassic -- perhaps 75 My later than currently envisioned. So, when did Golconda thrusting occur, and how does it fit into the Paleozoic-Mesozoic tectonic framework of western North America? These questions form the focus of this project and are being addressed through a multidisciplinary synthesis of geologic mapping, structural analysis, stratigraphy, and geochronology.

Assembly, Stabilization, and modification of Paleozoic-Mesozoic continental lithosphere, Idaho, Washington, and Oregon:
The paleogeography, timing, and kinematic characteristics of terrane accretion in the northwestern United States remain fundamental issues concerning the Mesozoic tectonic evolution of North America. At present, much of the area in western Idaho where these terranes are exposed has yet to be mapped in detail (1:24,000 scale or smaller). The need for geologic mapping and multidisciplinary data sets as a foundation for understanding the Mesozoic crustal assembly and younger tectonic modification in the region provides the principal scientific motivation for this research.